staging: rtl8723bs: remove set but not used variable 'bWifiBusy'

Fixes gcc '-Wunused-but-set-variable' warning:

 In function halbtc8723b1ant_TdmaDurationAdjustForAcl:
drivers/staging/rtl8723bs/hal/HalBtc8723b1Ant.c:1761:7: warning:
 variable bWifiBusy set but not used [-Wunused-but-set-variable]

It is never used so can be removed.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190726140321.19200-1-yuehaibing@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/hal/HalBtc8723b1Ant.c

@@ -1758,7 +1758,6 @@ static void halbtc8723b1ant_TdmaDurationAdjustForAcl(
 	static s32 up, dn, m, n, WaitCount;
 	s32 result;   /* 0: no change, +1: increase WiFi duration, -1: decrease WiFi duration */
 	u8 retryCount = 0, btInfoExt;
-	bool bWifiBusy = false;
 
 	BTC_PRINT(
 		BTC_MSG_ALGORITHM,
@@ -1766,11 +1765,6 @@ static void halbtc8723b1ant_TdmaDurationAdjustForAcl(
 		("[BTCoex], TdmaDurationAdjustForAcl()\n")
 	);
 
-	if (BT_8723B_1ANT_WIFI_STATUS_CONNECTED_BUSY == wifiStatus)
-		bWifiBusy = true;
-	else
-		bWifiBusy = false;
-
 	if (
 		(BT_8723B_1ANT_WIFI_STATUS_NON_CONNECTED_ASSO_AUTH_SCAN == wifiStatus) ||
 		(BT_8723B_1ANT_WIFI_STATUS_CONNECTED_SCAN == wifiStatus) ||